This proposal seeks to extend the Dietary Intervention Study in Children (DISC), a randomized clinical trial of dietary intervention in children with elevated LDL-cholesterol (LDL-C). The primary aims of the extension are to determine the long-term effect of intervention on LDL-C and total cholesterol measures and ascertain adult height. Sic clinical centers and a coordinating center were funded for DISC I in December, 1986, to carry out a clinical trial designed to assess the impact of such dietary intervention on children age 8-10 with elevated LDL-C levels. The clinical centers identified and enrolled 663 children (mean LDL-C 131 mg/dl and randomly assigned them to either an intervention or usual care control group. Dietary goals of intervention are <28% calories from fat, <8% from saturated fatty acids, 9% from polyunsaturated fatty acids, and <75 mg of dietary cholesterol per 1,000 Kcal. For DISC I, the primary efficacy outcome is the 36-month LDL-C and the primary safety outcomes are attained height and serum ferritin. Results to date indicate a significantly greater reduction of LDL-C in the intervention group compared to the control group at 12 and 36 months, with no significant adverse effects on growth. Extension of DISC is necessary to provide an unequivocal answer to the safety question regarding final adult stature. The present submission requests funding to follow the participants until they reach age 18. Maintenance dietary intervention will be provided to those participants in the intervention group and follow-up data collection will be made for all participants annually.